2 min read.Updated: 22 Jan 2021, 11:50 PM ISTLeroy Leo
The data for the 375-participant phase 1 trial, which has now been published in The Lancet, shows that Covaxin induced binding and neutralizing antibody responses against the novel coronavirus
NEW DELHI :
Bharat Biotech became the first Indian vaccine maker to have peer-reviewed data for its shots, after results from the company’s phase 1 trial to assess the safety and immunogenicity of Covaxin was published in The Lancet on Thursday.
“BBV152 (Covaxin) led to tolerable safety outcomes and enhanced immune responses. Both Algel-IMDG formulations were selected for phase 2 immunogenicity trials. Further efficacy trials are warranted," the results said.
Algel-IMDG is the adjuvant that Bharat Biotech is using in Covaxin to boost the immune response of the vaccine.
To be sure, Bharat Biotech had submitted data for its phase 1 and 2 studies through a pre-print, which is a non-peer-reviewed research result, last month.
The data for the 375-participant phase 1 trial, which has now been published in The Lancet, shows that Covaxin induced binding and neutralizing antibody responses against the novel coronavirus, and with the inclusion of the adjuvant, it is the first inactivated SARS-CoV2 vaccine that induces a T-cell response.
Antibodies are blood proteins that fight the virus from infecting human cells, while T-cells form an integral part of the body’s second layer of immune response against an infection.
Two doses of the vaccine and the placebo were given 14 days apart during the phase 1 trial, and the interim analysis was conducted 42 days after the first dose.
The dosing regimen has since changed to 28 days between the two shots.
Among the participants, one serious adverse event was reported five days after receiving the first shot of the vaccine. While it was initially reported as a “solicited adverse event", it was later classified as “not causally associated with the vaccine".
Even in terms of immunogenicity, about 82-92% of the participants in the three vaccine groups had antibodies against the novel coronavirus, SARS-COV2, after the second dose. However, it has to be noted that the immunogenicity data is interim and is traditionally conducted in a phase 2 study.
In its phase 2 study result, which was also released last month, the researchers had said that the indigenous vaccine induced immunity against covid-19 through antibodies as well as T-cells, and “hypothesized that the humoral and cell-mediated responses reported in this study may persist until at least 6-12 months after the second vaccination dose". The phase 2 result has not yet been published in a peer-reviewed journal.
Bharat Biotech’s Covaxin is currently in the third phase of its clinical trial, comprising 26,000 participants, to determine the efficacy of the vaccine.
Covaxin has had a controversial start since it was given an emergency licensure earlier this month based on only its safety and immunogenicity data. Its efficacy data is to be determined in the ongoing phase 3 trial, which started in mid-November. Many health experts have criticized the drugs regulator for giving Covaxin emergency use authorization despite the lack of crucial data.
To be sure, despite the controversy, Bharat Biotech is the only Indian vaccine maker in India to have published any data.
The other company that received emergency licensure for its vaccine in the country, Serum Institute of India, has not published any data from its local trials for Covishield, although there is phase 1-3 data from AstraZeneca, which has produced the original version of the vaccine.
Zydus Cadila, whose vaccine is currently in phase 3 efficacy trial, has not published any data, including that from its pre-clinical studies, for its three-dose vaccine ZyCoV-D.
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